There has been an increasing interest in the recovery of hydrocarbon materials from low and ultra-low permeability formations, such as tight oil and shale formations. Many wells have been drilled and completed in shale formations, such as the Eagle Ford Shale in the southern United States and the Duvernay Formation in western Canada. Some of these formations have been found to have an “upside down” distribution of fluids, where oil is in the shallowest zones, condensate in the middle, and dry gas is on the bottom of the structure. Further, unconventional distributions of fluids have been observed in tight formations such as the Nikanassin formation in western Canada, where gas is above an oil in the shallower zones, water is in a middle zone and additional gas is present on the bottom of the structure.
Due to their low permeability, there are many challenges in recovering of hydrocarbon material from such formations. Techniques, such as hydraulic fracturing, have been used to increase recovery of the hydrocarbons from these formations.
There exists a need for improved methods for recovering hydrocarbon materials from such formations.